Sat May 5 2007

Rivet removal HOWTO

I was starting to remove the main ribs from the right spar and I thought someone might find it useful to see my technique for removing rivets. It's kind of a dubious skill to have, but I'm afraid I've gotten rather good at removing rivets. Here's our demo rivet. It's a 1/8 inch universal head rivet.

Use a #40 drill and center it on the dimple in the head of the rivet.

Drill down just through the head of the rivet. This first step is critical. It's really important to get this hole centered very well on the head of the rivet.

Next, switch to a #30 drill.

...and again, drill only through the head of the rivet. When I say through the head what I mean is that the corner of the drill (where the conical face of meets the cylindrical sides of the drill), not the point, should be just through the head of the rivet.

Here's what it should look like.

You now need a 1/8 inch punch. It's important that the punch has a nice sharp edge to it.

Stick the punch in the rivet head...

Use it as a lever...

...and snap the rivet head off. If it doesn't want to snap off easily, try levering the other way. You may also need to drill a bit deeper, too.

As you can see, the rivet head has been removed, but I didn't drill through the rib material. If I had, it's likely that I would have opened up the hole which is bad.

After switching back to a #40 drill, drill down through the center of the rivet shank. It's not necessary to remove the rib before doing this just worked out that way in this case.

Note that it's very important to drill in the center of the rivet and drill it straight. If the drill gets off center, it'll open up the rivet hole in the spar (or whatever).

Drill down through the thickness of the spar, but not all the way through the shop head of the rivet. Basically what we're doing here is removing material from the core of the rivet to allow the sides of the rivet to squeeze in somewhat. That'll allow it to be pounded out more easily.

Use a 3/32 inch punch in the hole you just drilled...

Support the back side of the material with a socket that fits closely around the shop head of the rivet and tap it out. It shouldn't take a lot of heavy pounding.

Here's the rivet after removal. Note that the hole is centered in the shank of the rivet and doesn't break out through the side.

Rivet removal 101 complete. Class dismissed. :-)

I did this another 50 or 60 times to remove all the main ribs from the right spar. Afterward, I tweaked the spar flanges as on the left spar.